<!-- #docregion -->
<h1>Tour of Heroes ({{mode}})</h1>
<h3>Heroes:</h3>
<ul>
  <li *ngFor="let hero of heroes">
    {{hero.name}}
  </li>
</ul>
New hero name:
<input #newHeroName />
<button (click)="addHero(newHeroName.value); newHeroName.value=''">
  Add Hero
</button>
<div class="error" *ngIf="errorMessage">{{errorMessage}}</div>
